Generally speaking, this invention relates to an electronic switching control unit, which incorporates a display system, for running equipment. More particularly, this invention relates to a modular electronic switching/display system which is arranged to replace conventional electro-mechanical thumbwheel switches for controlling equipment. The modular electronic unit of the invention may be utilized in new equipment or as a retrofit for older equipment, in substituting for conventional thumbwheel switching devices.
The invention incorporates a microcontroller in combination with a random access memory in the form of a non-volatile random access memory (NOVRAM). Accordingly, the unit of the invention is fully programmable for providing switching codes and display messages. The unit of the invention may be combined with several other units which are connected as slave units with the master unit incorporating the microcontroller which controls all of the units in the series. The arrangement is such that great flexibility is provided in matching the electronic message unit of the invention to a user's particular application.
More specifically, the modular design of the invention allows for a single master unit which will control up to seven slave electronic message units. A four or five character matrix display may be utilized, in accordance herewith, with a light emitting diode display, a liquid crystal display, or a vacuum fluorescent display, as desired. Preferably, a liquid crystal display is utilized because of the low power requirements for such a display. With the arrangement here, the display is not limited to the small number of positions up to perhaps 12 utilized in a rotary wheel of the conventional thumbwheel switches of the past. With the invention here, up to 256 codes/messages are available. A 64-character automatic switch code vocabulary is available on each unit with an additional 50-character code available if a liquid crystal display unit is provided.
Each electronic message unit module has a two-button control, with each button for a particular direction in the sequence of characters available for display with the switches providing a higher or lower change in display by one position, depending upon which switch is actuated, or the arrangement is such that an automatic cycle may be provided with each movement or actuation of the switches through a variety of codes or messages, as required. As will be appreciated, with the utilization of the non-volatile random access memory in the units, in accordance herewith, the last code or message entered prior to power down is maintained when the unit is reactivated.
One object of this invention is, therefore, to provide a modular electronic switching and display system to replace a conventional electro-mechanical thumbwheel switching device for controlling equipment of all kinds.
A further object of the invention is to provide such an electronic message unit which allows much greater flexibility in matching the unit to specific applications without the need for a customer development of specific switches for specific applications. A further object of the invention is to provide an electronic message unit control arrangement wherein the size of the arrangement may be increased or decreased as required by the use of additional slave units controlled by the original single master unit for controlling several pieces of related equipment, as required.
Other objects and advantages of this invention will be apparent from the following description, the accompanying drawings, and the appended claims.